Yarn cutter for hosiery knitting machines

ABSTRACT

An improved stationary cutter element for use with the rotating cutter ring of a circular hosiery knitting machine having contiguous peripheral teeth extending into close proximity to the rotating circle of needles. The cutting edge of the stationary cutter element is properly shaped to be cammed upwardly as it engages the radially extending leading edges of successive teeth to provide a scissors action therewith and effectively cut any yarn engaged thereby.

United States Patent Minton [15] 3,654,778 [451 Apr. 11, 1972 [54] YARNCUTTER FOR HOSIERY KNITTING MACHINES [52] US. Cl. ..66/145 S [51] Int.Cl. ..D04b 15/61 [58] Field ofSearch ..66/134, 140, 140 S, 145, 145 S[56] References Cited UNITED STATES PATENTS 2,824,436 2/1958 Stack eta1. ..66/140 S 3,066,512 12/1962 Moody ..66/134 X 3,083,553 4/1963 DeMoss et a]. ..66/140 S 3,097,512 7/1963 Moyer ..66/145 S X 3,222,89212/1965 Moyer ..66/134 3,225,571 12/1965 Maller ..66/145 R X 3,283,54411/1966 Kent ..66/145 R X 3,488,679 l/l970 Boy ..66/134 FOREIGN PATENTSOR APPLICATIONS 1,376,419 9/1964 France ..66/145 S 1,542,833 9/1968France ..66/145 S 593,152 5/1959 Italy ..66/140 S PrimaryExaminer-Robert R. Mackey Attorney-Parrott, Bell, Seltzer, Park & Gibson[5 7] ABSTRACT An improved stationary cutter element for use with therotating cutter ring of a circular hosiery knitting machine havingcontiguous peripheral teeth extending into close proximity to therotating circle of needles. The cutting edge of the stationary cutterelement is properly shaped to be cammed upwardly as it engages theradially extending leading edges of successive teeth to provide ascissors action therewith and effectively cut any yarn engaged thereby.

9 Claims, 5 Drawing Figures YARN CU'I'IER FOR I-IOSIERY KNI'I'I'INGMACHINES This invention relates to improved yarn severing or cuttingmeans for circular hosiery knitting machines of the type which include arotating cutter ring provided with peripheral teeth extending into closeproximity to the circle of needles and adapted to engage yarnsintroduced and withdrawn from the needles.

In order to eliminate the long yam ends which are produced by cuttingdevices supported on the inner portion of the dial of a circular hosieryknitting machine, most circular hosiery knitting machines are currentlyprovided with a rotating cutter ring having teeth extending into closeproximity with the circle of needles and with some type of stationarycutter blade or element which is maintained in engagement with theteeth. The stationary cutter blade operates to cut any yarns engaged bythe teeth and brought into engagement with the cutter blade so that theyarn ends are cut closely adjacent the hosiery fabric. Many differenttypes of stationary cutting blade elements have been proposed for use incooperation with the rotating cutter ring.

These prior types of stationary cutter blades do not producesatisfactory yarn cutting results over a long period of time and thestationary cutter blade must be frequently resharpened so that a cleanand reliable cut is assured. Also, the known types of stationary cutterblade elements are not provided with means to accurately position thesame so that they operate satisfactorily with the rotating cutter ring.The known types of stationary cutter blades also fail to cut onoccasion, because of foreign substances being carried under the cutterblade by the rotating cutter ring so that the cutter blade is raisedfrom the surface of the ring.

With the foregoing in mind, it is an object of the present invention toprovide an improved stationary cutter blade for cooperation with therotating cutter ring which operates to effectively cut the yarn endsover a long period of time and while requiring very little attention onthe part of the operator.

It is another object of the present invention to provide an improvedstationary cutter blade which may be easily adjusted into proper settingrelationship with the teeth of the rotating cutter ring and wherein theaction between the cutting edge of the successive teeth and the cuttingedge of the stationary cutter blade provides a scissors action whichinsures the effective cutting of the yarn.

In accordance with the present invention, the improved cutter includes asubstantially rectangular lower end having a leading cutting edgeextending at an acute angle and an outside edge extending at a rightangle from the leading cutting edge to provide an outer cutter point attheir juncture. The leading cutting edge extends upwardly and inwardlyfrom the outer cutter point and the outside edge extends upwardly andrearwardly from the outer cutter point to provide what may be termed acompound angle" on the lower end of the cutter element. Resilient meansis provided for urging the cutter element downwardly into engagementwith the upper surface of the cutter ring so that the leading cuttingedge is cammed upwardly as it engages the radially extending leadingedges of successive teeth of the rotating cutter ring to provide ascissors action therewith and effectively cut any yarn engaged thereby.Air under pressure is directed downwardly against the upper surface ofthe rotating cutter ring and immediately in advance of the cutter bladeto remove any foreign substance being carried toward the stationarycutter blade by the cutter ring.

Other objects and advantages of the present invention will becomeapparent in connection with the following detailed description of thedrawings, in which- FIG. 1 is a fragmentary isometric view of a portionof the dial of a circular hosiery knitting machine and illustrating thestationary cutter blade of the present invention associated with therotating cutter ring;

FIG. 2 is a vertical sectional view at an enlarged scale and being takensubstantially along the line 2-2 in FIG. 1;

FIG. 3 is a vertical sectional view taken substantially along the line3-3 in FIG. 2;

FIG. 4 is an enlarged horizontal sectional view taken substantiallyalong the line 4-4 in FIG. 1; and

FIG. 5 is a greatly enlarged fragmentary front elevational view of thelower portion of the stationary cutter blade and a small portion of therotating cutter blade to illustrate the manner in which the compoundangle on the lower end of the cutter blade cooperates with the teeth ofthe cutter ring.

Only those portions of a circular hosiery knitting machine areillustrated which are necessary to an understanding of the presentinvention. As is well known, most circular hosiery knitting machinescurrently in use are of the multiple feed type and are provided with aplurality of yarn feeding and knitting stations spaced around the needlecylinder so that a plurality of courses are knit with each rotation ofthe needle cylinder. A stationary dial is supported inside of therotating circle of needles, as indicated at N in FIG. 4, and usuallyincludes a dial plate 10. The dial plate supports the usual cams, notshown, for controlling the radial position of transfer bits 11 (FIG. 3)which are supported in the radial grooves of a rotating dial bed 12,rotating in timed relationship with rotation of the circle of needles N.A rotating cutter ring 13 is supported for rotation on the dial plate 10and is rotated in time relationship to rotation of the circle of needlesN by a driving connection with the dial bed 12.

Contiguous teeth are provided on the rotating cutter blade 13 and eachof the teeth includes a radially extending leading edge 14 and atrailing edge 15 which extends at an acute angle from the radiallyextending leading edge 14. The peripheral teeth extend into closeproximity with the circle of needles N and are adapted to engage yarnsintroduced and withdrawn from the needles during the knitting of ladiesseamless hosiery and the like.

As is well known, yarn feed fingers, not shown, are provided forintroducing and withdrawing yarn to the needles at each knittingstation. When a yarn is introduced, the first needle to knit pulls theyarn downwardly from where its terminal end is held by suitable means,such as a suction nozzle 20. The suction nozzle 20 is supported in asuitable dial cap 21 so that the yarn is drawn downwardly and over therotating cutter ring 13. As the cutter ring 13 rotates with the circleof needles N, the corresponding leading edge 14 of a tooth carries theyarn around with the needles until it engages and is cut by thestationary cutter blade, to be presently described.

When a yarn is withdrawn from active position, the corresponding yarnfeed finger is raised so that the yarn extending from the last needle toknit is engaged by the leading edge 14 of a tooth on the rotating cutterring 13 and is carried around the needle cylinder until it engages thefixed cutter blade. Upon severing of this withdrawn yarn, the cut freeend is drawn up into the suction nozzle 20 and held until the yarn isagain introduced. Suction is provided beneath the dial cap to attractthe yarn ends up into the suction nozzle 20 by means of an air pressureline 22 which directs air upwardly in the suction nozzle 20.

In accordance with the present invention, an outwardly extending flangeor skirt-like extension is provided on the dial cap 21 and ahead of thestationary cutter element. This skirtlike extension 25 extendsdownwardly and overlies the outer edge of the teeth of the rotatingcutter blade 13 and provides a tunnel like entranceway above the uppersurface of the rotating cutter blade 13 and in advance of the stationarycutter blade. A vertically extending opening 26 is provided in theextension 25 to provide an opening for operation of the stationarycutter of the present invention, broadly referred to at C.

The stationary cutter C includes an elongate cutter element which issubstantially rectangular in cross-section and has a vertically disposedupper stem portion 30. The upper stern portion 30 is supported forvertical movement in a guide slot or groove 31 cut in a vertical portion32 of a support bracket having a horizontal leg 33. The horizontal leg33 is fixedly secured to the dial cap 21 by screws 34. Suitableadjustment screws 35, 36 (FIG. 3) are threadably supported in one sideof the vertical housing portion 32 and a single adjustment screw 37 isthreadably supported in the opposite side of the housing 32 andsubstantially half way between the screws 35, 36. The slot 31 isconsiderably wider than the width of the stem portion of the fixedcutter C and the inner ends of the adjustment screws 35, 36 and 37 maybe adjusted to vary the vertical position of the stern portion 30, forpurposes to be presently described.

A spring perch, in the form of a screw 40, is threaded through the upperend of the stern portion 30 and supports the upper end of a tensionspring 41. The lower end of the tension spring 41 is fixed in a bore 42extending vertically in the vertical housing portion 32 (FIG. 2). Thetension spring 41 thus resiliently urges the cutter element C downwardlyso that its lower end is resiliently maintained in engagement with theupper surface of the rotating cutter ring 13.

The lower end portion of the fixed cutter C is substantially rectangularand includes a hardened steel blade element which is suitably brazed tothe leading surface thereof. The lower end of the cutter C includes aleading cutting edge 44 (FIG. 4) extending at an acute angle whichsubstantially corresponds to the angular disposition of the trailingedges 15 of each of the teeth on the rotating cutter blade 13. Anoutside edge 45 is also provided at the lower end of the cutter blade Cand extends at a right angle from the leading edge 44. The juncture ofthe leading cutting edge 44 and the outside edge 45 defines an outercutter point 46 which constitutes the lowermost point of the lower endof the cutter C (FIG. 5). As shown in FIG. 5, the lower end of thecutter blade is cut at a compound angle with the leading cutting edge 44extending upwardly and inwardly from the outer cutter point 46 at aslight angle of approximately one-half degree as indicated at A. Theoutside edge 45 extends upwardly and rearwardly from the outer cutterpoint 46 at a slight angle of approximately 3, as indicated at B.

The adjustment screws 35, 36, and 37 are regulated so that the outercutting point 46 is positioned to correspond with the outer extremitiesof the teeth on the cutter ring 13, substantially as shown in FIG. 4. Asthe teeth of the cutter ring 13 move beneath the cutter blade C, theleading edge 14 of each tooth engages the inclined leading edge 44 ofthe cutter and a camming action takes plate so that the leading cuttingedge is cammed upwardly as the radially extending leading edge 14 of thetooth moves to the outer cutter point 46. This camming action provides ascissors action therewith to effectively cut any yarn broughttherebeneath by the teeth.

As the outer end of a tooth moves into alignment with the lower cutterpoint 46, the cutter blade C is raised slightly. With further movementof the ring 13, the cutter blade C is lowered slightly as the trailingedge 15 of the tooth engages the inclined outside edge 45 so that theouter cutter point 46 is actually positioned below the upper level ofthe rotating cutter blade 13, as shown in FIG. 5. With further rotationof the cutter 13, the cutter blade C is again raised slightly as theleading edge 14 of the next tooth engages the leading cutting edge 46and cams the same upwardly.

Thus, a scissors action takes place between the leading edge 14 of eachtooth and the leading edge 44 of the fixed cutter C as each tooth of therotating ring 13 passes therebeneath. This scissors action insures thatany yarn carried therebeneath by the teeth will be accurately andeffectively cut.

In order to prevent foreign matter from being brought beneath the fixedcutter C by the rotating blade 13, the lower end of an air pressure tube50 is positioned in the opening 26 and is positioned closely adjacentthe leading cutting edge 44. The air pressure tube 50 extends upwardly(FIG. 1) and its upper end is supported in a support bracket 51 which issuitably secured to the vertical housing portion 32. An air pressurebranch line 52 is connected at one end to the upper end of the tube 50and its other end is suitably connected to the air pressure line 22.Thus, air under pressure is continuously directed downwardly against theupper surface of the blade 13 (FIG. 4) and moves outwardly along theblade to remove any lint, yarn ends, and the like which would becometrapped under the cutter C.

Although the cutter C is illustrated as being resiliently urged into theengagement with the upper surface of the rotating cutter blade 13 in acontinuous manner, it is to be understood that this cutter blade may beadapted to be raised to an inoperative position when no yarn ends are tobe cut.

In the drawings and specification, there has been set forth a preferredembodiment of the invention, and although specific terms are employed,they are used in a generic and descriptive sense only and not forpurposes of limitation.

What is claimed is:

1. In a circular hosiery knitting machine including a circle of needlessupported for rotation, a stationary dial supported inside of saidcircle of needles, a cutter ring mounted for rotation on said stationarydial and having contiguous peripheral teeth extending into closeproximity to said circle of needles, each of said teeth including aradially extending leading edge and a trailing edge extending at anacute angle therefrom, said leading edges being adapted to engage yarnsintroduced and withdrawn from the needles, the combination therewith ofan improved cutter supported on said dial and comprising a. an elongatecutter element including a substantially rectangular lower end defininga leading cutter edge extending at an acute angle substantiallycorresponding to the acute angular relationship of said trailing edgesof said teeth, and an outside edge extending at a right angle from saidleading cutting edge,

b. the juncture of said leading cutting edge and said outside edgedefining an outer cutter point corresponding with the outer extremitiesof said teeth,

c. said leading cutting edge extending upwardly and inwardly from saidouter cutter point at a slight angle, and said outside edge extendingupwardly and rearwardly from said outer cutter point at a slight angleso that said outer cutter point is the lowermost point of the lower endof said cutter element, and

d. means resiliently urging said cutter element downwardly intoengagement with the upper surface of said cutter ring so that saidleading cutting edge is cammed upwardly as it engages said radiallyextending leading edges of successive teeth of said rotating cutter ringto provide a scissors action therewith and effectively cut any yarnengaged thereby.

2. A cutter according to claim 1 wherein said elongate cutter elementincludes a vertically disposed upper stem portion, and means foradjusting the vertical position of said upper stem portion to therebyvary the position ofsaid outer cutter point relative to the outerextremities of said teeth.

3. A cutter according to claim 2 including a support bracket carried bysaid stationary dial and comprising a vertical housing portion with avertical groove therein for slideably supporting said stem portion, andwherein said adjusting means comprises a pair of spaced apart screwsextending through said vertical housing portion with their inner ends inengagement with one side of said stem portion, a single screw extendingthrough said vertical housing portion with its inner end in engagementwith the other side of said of stem portion, and said single screw beingspaced substantially half the distance between said pair of screws.

4. A cutter according to claim 3 wherein said housing portion includes avertically disposed bore extending parallel to said vertical groove, andwherein said resilient means (d) comprises a tension spring having anupper end connected to the upper end of said stern portion and having alower end connected adjacent the lower end of said bore.

5. A cutter according to claim 1 including a hardened steel plate fixedon the lower leading edge of said cutter element.

6. A cutter according to claim 1 including means for directing air underpressure onto the upper surface of said cutter ring and in front of saidcutter element to remove foreign substances carried toward said cutterelement by said cutter ring.

7. A cutter according to claim 6 wherein said stationary dial includes adial plate and a dial cap overlying said dial plate, a skirt-likeextension extending outwardly from said dial cap and over said cutterring and having an opening therein to receive said cutter element, andwherein said air pressure proximately one-half of a degree.

9. A cutter according to claim 1 wherein said outside edge extendsupwardly and rearwardly at an angle of approximately 3.

1. In a circular hosiery knitting machine including a circle of needlessupported for rotation, a stationary dial supported inside of saidcircle of needles, a cutter ring mounted for rotation on said stationarydial and having contiguous peripheral teeth extending into closeproximity to said circle of needles, each of said teeth including aradially extending leading edge and a trailing edge extending at anacute angle therefrom, said leading edges being adapted to engage yarnsintroduced and withdrawn from the needles, the combination therewith ofan improved cutter supported on said dial and comprising a. an elongatecutter element including a substantially rectangular lower end defininga leading cutter edge extending at an acute angle substantiallycorresponding to the acute angular relationship of said trailing edgesof said teeth, and an outside edge extending at a right angle from saidleading cutting edge, b. the juncture of said leading cutting edge andsaid outside edge defining an outer cutter point corresponding with theouter extremities of said teeth, c. said leading cutting edge extendingupwardly and inwardly from said outer cutter point at a slight angle,and said outside edge extending upwardly and rearwardly from said outercutter point at a slight angle so that said outer cutter point is thelowermost point of the lower end of said cutter element, and d. meansresiliently urging said cutter element downwardly into engagement withthe upper surface of said cutter ring so that said leading cutting edgeis cammed upwardly as it engages said radially extending leading edgesof successive teeth of said rotating cutter ring to provide a scissorsaction therewith and effectively cut any yarn engaged thereby.
 2. Acutter according to claim 1 wherein said elongate cutter elementincludes a vertically disposed upper stem portion, and means foradjusting the vertical position of said upper stem portion to therebyvary the position of said outer cutter point relative to the outerextremities of said teeth.
 3. A cutter according to claim 2 including asupport bracket carried by said stationary dial and comprising avertical housing portion with a vertical groove therein for slideablysupporting said stem portion, and wherein said adjusting means comprisesa pair of spaced apart screws extending through said vertical housingportion with their inner ends in engagement with one side of said stemportion, a single screw extending through said vertical housing portionwith its inner end in engagement with the other side of said of stemportion, and said single screw being spaced substantially half thedistance between said pair of screws.
 4. A cutter according to claim 3wherein said housing portion includes a vertically disposed boreextending parallel to said vertical groove, and wherein said resilientmeans (d) comprises a tension spring having an upper end connected tothe upper end of said stem portion and having a lower end connectedadjacent the lower end of said bore.
 5. A cutter according to claim 1including a hardened steel plate fixed on the lower leading edge of saidcutter element.
 6. A cutter according to claim 1 including means fordirecting air under pressure onto the upper surface of said cutter ringand in front of said cutter element to remove foreign substances carriedtoward said cutter element by said cutter ring.
 7. A cutter according toclaim 6 wherein said stationary dial includes a dial plate and a dialcap overlying said dial plate, a skirt-like extension extendingoutwardly from said dial cap and over said cutter ring and having anopening therein to receive said cutter element, and wherein said airpressure directing means comprises an air pressure tube extendingthrough the opening in said skirt-like extension and having a free endterminating above said cutter ring.
 8. A cutter according to claim 1wherein said leading cutting edge extends upwardly and inwardly at anangle of approximately one-half of a degree.
 9. A cutter according toclaim 1 wherein said outside edge extends upwardly and rearwardly at anangle of approximately 3*.